Overview

The National Climate Extremes Committee (NCEC) was established in 1997 to assess the scientific merit of extreme meteorological/climatological events and provide a recommendation to NOAA management regarding the validity of related meteorological measurements. The NCEC is also responsible for disseminating NOAA's recommendation of the event and coordinating any media inquiries with the appropriate public affairs offices.

The Committee is chaired by a representative from the National Climatic Data Center (NCDC) and composed of additional representatives from the National Weather Service's (NWS) Office of Climate, Water, and Weather and a designated representative from the American Association of State Climatologists (AASC). Discussions on the role of the Committee and its interaction with the state climatologist community will be conducted at the annual meeting of the AASC.

The Federal Committee's mandate is restricted to national extreme values of the elements listed in the section below. Included in this section are the previously accepted national extremes, along with the location and date of each occurrence. The Committee's mandate does not include the reevaluation of the existing extreme values listed. This list may be expanded as additional element extremes, such as greatest monthly rainfall/snowfall, are developed. Some elements, such as short-duration rain rates, are frequently reported in the media. Because they are anecdotal and non objective in nature, the Committee will not be responsible for validating reports of this nature.

Extreme values which do not affect national records will be validated using current procedures. Local daily/monthly/annual records at sites operated by the National Weather Service, Federal Aviation Administration and military installations, will be the responsibility of on-site personnel. State records for most listed elements are maintained at the National Climatic Data Center and new records will be validated via communication between NCDC, NWS and the state climatologist for the state in question. If the state does not have an active state climatologist program, coordination will be with the Director of the Regional Climate Center (RCC) covering the state. NCDC will update the list of state records with any reports validated through this procedure.

If, in the judgment of the NWS and the National Climatic Data Center, a national extreme value warrants investigation, the NCEC will assemble a team with the geographical and technical expertise required to determine the accuracy of the reported extreme.

For national extremes reported from NWS sites, the measurement will be examined for compliance with established NWS guidelines and specifications. Specifically, the investigating team will assess observational procedures, instrument exposure and operation, along with reporting equipment maintenance and calibration. At a minimum, the investigating team will be composed of personnel from the site in question (for WSO sites) or the NWS Cooperative Program Manager for cooperative sites, instrument and observational procedures specialists from NWS headquarters, and the state climatologist, or if necessary, a representative from the RCC covering the state in question. Additionally, the state climatologist or RCC representative from the state with the current national record will also be invited to participate as a member of the investigating team.

For national extremes reported from local meso-networks, the team should include the mesonet service technician, head of the mesonet, the local NWS Cooperative Program Manager, instrument and observational procedure specialists from NWS headquarters, and state climatologists or RCC representatives covering the state with the current extreme record and potential record.

For national extremes reported from a military location, the Office of the Federal Coordinator for Meteorological Services will coordinate communication between the military instrument and observational specialists, NWS personnel and the requisite state climatologist/RCC representatives

Although the frequency of new national records requiring team investigations is expected to be minimal, the associated expense for state climatologists/RCC representatives may present a financial burden. The NWS will consider development of a funding mechanism to cover costs for non-National Oceanic and Atmospheric Administration (NOAA) personnel involved in any studies.

During the course of the investigation of a national extreme, the NCEC will maintain liaison with the investigating team and will provide a coordinated response to the NOAA NWS Public Affairs Office for the handling of media inquiries on the status of the investigation and validity of the report. Once the investigating team has finalized its report, the NCEC will provide a recommendation on the event to the Director of the NCDC, who will in turn determine the declaration. The NCEC will report on the decision.